It'll highly depend on your soundcard, speakers AND your hearing, but mainly your soundcard and your speakers.As a child I could hear well above 20kHz, now from the site, and with David's EM3's connected to my laptop, I could clearly hear all upto 18kHz.19kHz if I put my left ear straight in front of the monitor. 20kHz I can feel, but not hear. I know there's an annoying sound, but can not identify it (eg: can not pinpoint it very well, and can not say if it fluxuates in frequency).Probably because I generally play on moderate volume stages. We never go out of hand, never really use more than 500W (most of the time 300W) for the bass, and a couple of 200W 12" monitors.

Should I at every gig stand next to a drummer with crashing cymbals right next to my ear (which I was one time), I'd probably be deaf in one ear.

Yeah, me likey low notes, too! I love the power of blowing an ego inflated guitarist through the wall.

One of my guitarists has some hearing damage on the high end. To compensate, he used to crank the schmitt out of his highs so that it sounded normal to him. It was KILLING the rest of us. It took forever for him to understand that he didn't sound good. We were in the studio one day and the engineer said "You set your tone like someone who has severe hearing damage. I see that a lot in this type of work. You may not even realize it, but you're compensating for it."

He finally took our tonal advise at that point.

DNA 1350 and 410-4: Why settle for really good tone when you can have the best?